Ultra II 4.0 not recognized in 1 year old Dell XPS

Just purchased an Ultra II 4.0 that does not work in my 1 year old DELL XPS 410 with multiple card reader interfaces. Also the Ultra does not work with the supplied SDDR-113 card reader in this desktop but it does work in 2 older laptop computers through the USB port connection. Dell tech support cannot confirm I have or don't have an SDHC device! I don't see any product info or downloads for the SDDR-113 or card to help me troubleshoot the compatibility problem. Any suggestions?